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The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
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The https:// ensures that you are connecting to the
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and transmitted securely.
Table representation of search results timeline featuring number of search results per year.
| Year | Number of Results |
|---|---|
| 1968 | 2 |
| 1969 | 1 |
| 1970 | 1 |
| 1971 | 2 |
| 1972 | 2 |
| 1973 | 2 |
| 1974 | 1 |
| 1975 | 1 |
| 1977 | 1 |
| 1978 | 1 |
| 1979 | 1 |
| 1981 | 1 |
| 1988 | 1 |
| 1989 | 1 |
| 1996 | 1 |
| 2003 | 1 |
| 2006 | 1 |
| 2007 | 1 |
| 2008 | 1 |
| 2013 | 1 |
| 2014 | 1 |
| 2015 | 3 |
| 2016 | 7 |
| 2017 | 3 |
| 2018 | 3 |
| 2019 | 7 |
| 2020 | 12 |
| 2021 | 10 |
| 2022 | 16 |
| 2023 | 8 |
| 2024 | 3 |